1. Field of the Invention
The present invention relates to a robot system which takes out an object by using a robot, wherein a roller device is arranged on a finger of a hand of the robot.
2. Description of the Related Art
In the prior art, there is a known robot having a camera for detecting an object to be take out and a grip-type hand. For example, Japanese Unexamined Patent Publication (Kokai) No. 2004-230513 discloses a work taking out robot wherein a hand having a gripping means and sensor head are attached to a front end of a robot arm, and the posture of the hand is properly changed based on an image of the workpiece obtained by the sensor head.
Further, Japanese Unexamined Patent Publication (Kokai) No. 2005-317854 discloses a transfer robot having a hand for holding a plate-like workpiece in a horizontal state, wherein a plurality of rollers and a rotational driving mechanism for rotating the rollers are arranged to the hand so as to convey the workpiece in the horizontal direction.
In the device of Japanese Unexamined Patent Publication (Kokai) No. 2004-230513, the posture of the hand is properly changed so as to grip the workpiece to be taken out, corresponding to the posture of the workpiece or an overlapping state of the workpieces. However, the device does not have a function for purposely introducing the workpiece within the hand. Therefore, when the workpieces are adjacent to each other, another workpiece adjacent to the objective workpiece may be an obstacle, whereby the objective workpiece may not be gripped.
On the other hand, in Japanese Unexamined Patent Publication (Kokai) No. 2005-317854, the hand with the roller device has a flat hand surface. Therefore, although the hand can convey workpieces which are supplied in an orderly manner, the hand cannot easily take out or convey workpieces having various shapes which are randomly located.